package com.guigu.gulimall.product.service.impl;

import org.springframework.stereotype.Service;

import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;

import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.guigu.common.utils.PageUtils;
import com.guigu.common.utils.Query;

import com.guigu.gulimall.product.dao.CategoryDao;
import com.guigu.gulimall.product.entity.CategoryEntity;
import com.guigu.gulimall.product.service.CategoryService;


@Service("categoryService")
public class CategoryServiceImpl extends ServiceImpl<CategoryDao, CategoryEntity> implements CategoryService {

    @Override
    public PageUtils queryPage(Map<String, Object> params) {
        IPage<CategoryEntity> page = this.page(
                new Query<CategoryEntity>().getPage(params),
                new QueryWrapper<CategoryEntity>()
        );

        return new PageUtils(page);
    }


    @Override
    public List<CategoryEntity> listWithTree() {
        //1 查查所有分类
        List<CategoryEntity> entityList = this.list();

        //2 组装成父子结构
        entityList.stream()
                .filter(categoryEntity -> categoryEntity.getParentCid() == 0)
                .map((menu)->{ menu.setChildren(getChildren(menu,entityList));return menu; })
                .sorted((menu1,menu2) -> {
                   return  (menu1.getSort() == null ? 0 : menu1.getSort()) - (menu2.getSort() == null ? 0 : menu2.getSort());
                })
                .collect(Collectors.toList());


        return entityList;
    }

    /**
     * 递归获取子节点数据
     * @param menu
     * @param all
     * @return
     */
    private List<CategoryEntity> getChildren(CategoryEntity menu, List<CategoryEntity> all) {

        List<CategoryEntity> children = all.stream()
                .filter(categoryEntity -> menu.getCatId() == categoryEntity.getParentCid())
                .map(categoryEntity -> {
                    categoryEntity.setChildren(getChildren(categoryEntity, all));return categoryEntity; })
                .sorted((menu1,menu2) -> {
                    return  (menu1.getSort() == null ? 0 : menu1.getSort()) - (menu2.getSort() == null ? 0 : menu2.getSort()); })
                .collect(Collectors.toList());

        return children;

    }
}
